In the diagnosis and monitoring of diseases, medical tests are often performed on blood, tissue, or other media sampled from patients. Such tests are often performed on automated testing machines. In a typical scenario, a doctor requests that a particular test be performed, and a sample is taken from the patient. The sample is sent to an on-site or off-site testing lab, and the results of the test are returned to the doctor for review and reporting to the patient.
In order to ensure proper diagnosis and treatment, a medical testing machine should be calibrated before its first use and periodically thereafter.